For some receiving applications, active antennas may be a good choice. You can even buy them on Amazon (Sony AN-LP1, MFJ-1020C). Many shortwave listeners use active antennas they can use them over a wide frequency range and are very small.
To learn more about active antennas, you can download a new Rohde&Schwarz application note, “Active Antennas for Radiomonitoring.” This application note:
- Describes how active antennas work.
- Explains their characteristic parameters, including:
- impedance
- antenna factor
- antenna noise
- sensitivity
- gain
- non-linear distortion
- dynamic range
- Gives examples of how to use them.
The final section, for example, describes how to use them for HF reception. It discusses how the ionosphere affects signal polarization, how to select an appropriate antenna, and the effects of installation height.
The antennas described by this app note are really a step (or two) above the kinds of active antennas that most SWLs and hams use, and the app note includes more than you’ll probably want to know about them. But, it will give you something to think about if you’re tempted to plunk down $100 or more for that Sony or MFJ antenna.
Dear Dan
Hello, I have a question about Antenna Factor, if we choose the antenna with Low AF, we will have what advantage.
Hope to hear from you.
thanks
Hi Marz,
I’m certainly no expert, but it seems to me that you want an antenna with a high antenna factor, as long as having a high AF doesn’t make it too noisy.